1. Field of the Invention
This invention generally relates to a recording apparatus using a thermal printhead and in particular to a thermal recording apparatus having a platen roller which may be moved between operative and inoperative positions depending on the mode of operation of the apparatus.
2. Description of the Prior Art
A thermal recording apparatus, such as a thermal printer, includes a thermal printhead and a platen roller between which a sheet of recording paper, typically heat-sensitive paper, is passed. The thermal printhead is normally provided with a plurality of heat-producing or resistor elements arranged in the form of a single array and the sheet of heat-sensitive paper is transported by the platen roller as pressed against the thermal printhead, in particular, its array of heat-producing elements. Heat pulses are applied to the array of heat-producing elements selectively in accordance with image information to be recorded, and thus the heat-producing elements are selectively activated by the heat pulses to define a heat pattern which in turn is applied to the sheet of heat-sensitive paper. As a result, a color producing layer of the heat-sensitive paper is selectively melted to thereby record an image on the heat-sensitive paper.
However, in such a conventional thermal recording apparatus, since the sheet of heat-sensitive paper is always pressed against the heat-producing elements of the thermal printhead by the platen roller, there is a chance that the heat-sensitive paper becomes stuck to the thermal printhead and/or to the platen roller or undesired recording is effected to the heat-sensitive paper due to residual heat remaining in at least some of the heat-producing elements upon completion of intended recording.